If you’re doing histological research on mouse intestines, many of the rules that are used for human tissue samples apply. However, Ka Lam Nguyen, who is currently earning a PhD from the University of Illinois, Urbana-Champaign, points out that the difference in size has a huge impact on how samples must be handled.
Given that smaller size, the following are techniques researchers use to effectively examine mouse tissue.
Swiss roll preparation
If you’re doing a longitudinal section, Nguyen says this preparation—where researchers roll the mouse intestine to resemble the type of cake that shares its name—is the best choice since it allows you to see the entire GI tract in one slide. However, he says the Swiss roll method isn’t ideal if you want to examine stomach or cecum samples since they are much shorter.
Additionally Nguyen stresses the importance of removing feces prior to rolling the sample.
“If your tissue during grossing is not cleaned out, what happens is that when you start sectioning during microtomy, you're going to have a lot of tears and you're going to run through those disposable blades quickly because the feces in a mouse is just full of undigestible fibrous plant matter. That will wear down your knife a lot and you will not get a very good section,” said Nguyen. “For any type of intestinal research, especially in the mouse, you definitely have to clean all of the feces out.”
Intestine strips
This method is easy and versatile, so you can examine samples cross-sectionally or longitudinally. As a result, intestine strips allow researchers to focus on the specific section of the GI tract they want to examine. However, when you cut samples into strips, there is an important limitation to keep in mind.
“The downside for this is that you can only examine small regions at a time,” Nguyen said. “You cannot visualize the entire mouse GI tract, so this is actually not very suitable if you know your research model has a lot of different regional differences.”
Gut bundling
The gut bundling method is similar to the intestine strips technique, though it cannot be used with stomach or cecum samples. When gut bundling, researchers cut samples into small strips and then tape them together into a bundle that allows them to examine more regions of tissue at one time. Also, like intestine strips, there are limitations to this method.
“It's basically an upgraded version of the intestinal strips method, but the downside to this is that it's only suitable for cross-sectional studies,” said Nguyen. “If you want to examine the whole mouse GI tract at once, it's not going to be able to do that.”
While many of the histological techniques used for human tissue can be applied to mouse intestines, researchers must account for the size differences that require special handling. Techniques like the Swiss roll, intestine strips, and gut bundling offer unique advantages and limitations depending on the research focus. Whether aiming for a comprehensive view of the GI tract or targeting specific regions, understanding the nuances of each preparation method is crucial. To learn more about these three methods, check out the NSH “Histological Processing Techniques for Mouse Intestines in Research” webinar here where you will also get information on common GI artefacts, choosing fixatives when doing mouse GI research, and intestine processing steps.
#2024#Discussion
#Blog#GeneralAnatomicPathology